I've looked through the posts on allergies and haven't found a close enough match to what we're going through here. Ponta, just turned four, has had a few summers of leg-gnawing and fur-stripping, but this summer he's outdoing himself. We live in Tokyo, and even before the 95º temps and 65% humidity, he was biting and licking his fur away. He concentrates on his legs: the top of his forelegs, and the forward parts of his haunches, and has pretty much stripped the fur from those parts. He's started going after his hindquarters, on his side above his legs, and the fur is thinning.

We took him to the vet who did a blood test and the vet reported that nothing came up. The doctor the put him on 50mg a day of Cyclosporine. I tried to suggest Benadryl, but the doctor just shrugged that off the moment I showed him the name and refused to listen to the idea when I brought it up again.

We tried switching Ponta to a no-grain, fish-based dog food, which he liked for all of one day, and then pretty much hated. Since my wife is incredibly weak-willed and will cave and feed him what he wants within just a few hours, we haven't had much success keeping him on a strict diet.

Nevertheless, Ponta has show a bit of improvement—he doesn't lick and gnaw as much as he used to, we only catch him doing it a bit now and then.

What's gotten me more worried, however, is that now he's showing a dark mottling on his legs where there is bare skin. Has anyone seen this before, and do you know what it is? Is it just part of the healing process, or a worrying development?

Does anyone have any suggestions? Is this just a general thing that Shibas will do during the summer months? Is it possible we have a less-than-top-nitch vet and should try a new one? Should we stay the course, continue with the Cyclosporine (it takes a few weeks to kick in, right?), and try to get him back on the non-grain fish feed?

Cyclosporine is more commonly known as Atopica, so you may find more info searching for that. It does help many dogs, but can have serious side effects. As with steroids, not recommended for long term use. And must be weaned off gradually.

Benadryl is over the counter and generally safe, but Atopica is more effective. You should not need both. (I have only found benadryl successful at making a dog sleepy.)

His skin actually looks pretty good, not red or broken and inflamed. Was it worse before the Atopica? The blackness is temporary. But since it is bare, keep it clean and avoid over exposure to the sun to prevent a burn.

"Black skin disease" is actually hyper pigmentation as a result of skin damage to the dermal layer of skin due to scratching and or licking with increased bacteria load. Skin goes pinks to purp. light gray to black. In severe cases year after year without treatment, the hair may not grow back at all, or damage will be permanent if too many allergy flares.

Thank you! A fantastic answer, much appreciated! Good to know that the black skin thing is not a worrying sign, but we should take care about this in the future. Sorry I did not find the varied answers on my own, sometimes it's hard to know the right keywords. We're taking him back to the vet later today, I'll ask about the skin test then.